Closed motive power system utilizing compressed fluids

ABSTRACT

Stored energy in a compressed elastic fluid is utilized in a controlled manner to pressurize an inelastic fluid and to maintain such pressurization. The pressurized inelastic fluid is throttled to the impeller of a prime mover. A portion only of the output energy from the prime mover is utilized to operate a circulating means for the inelastic fluid so as to maintain a nearly constant volumetric balance in the system.

United States Patent 1 van Valkinburgh [451 July 10,- 1973 CLOSED MOTIVEPOWER SYSTEM 3,563,032

UTILIZING COMPRESSED FLUIDS [75] Inventor: Eber H. Van Valkinburgh,Reno,

' Nev.

[73] Assignee: Endless Power Corporation, Inc.,

Reno, Nev.

[22] Filed: Nov. 11, 1971 [21] Appl No.: 197,667

[52] US. Cl. 60/468, 60/33 [51] Int. Cl. F03b 1/00, FlSb 1/02 [58] Fieldof Search 60/5l, 55, 54

[56] References Cited UNITED STATES PATENTS 3,163,985 1/1965 Bouyoucos60/51 2/1971 La Pointe 60/51 Primary Examiner-Edgar W; GeogheganAttorney-Rupert J. Brady et al.

[57] ABSTRACT Stored energy in a compressed elastic fluid is utilized ina controlled manner to pressurize an inelastic fluid and to maintainsuch pressurization. The pressurized inelastic fluid is throttled to theimpeller of a prime mover. A portion only of the output energy from theprime mover is utilized to operate a circulating means for the inelasticfluid so as to maintain a nearly constant volumetric balance in thesystem.

12 Claims, 5 Drawing Figures PATENIED JUL 1 mars SHEUIIIZ CLOSED MOTIVEPOWER SYSTEM UTILIZING COMPRESSED FLUIDS The objective of the inventionis to provide a closed loop power system which utilizes the expansiveenergy of a compressed elastic fluid, such as air, to pressurize andmaintain pressurized throughout the operational cycle of the system asecond non-elastic and noncompressible fluid, such as oil. Thepressurized nonelastic fluid is released in a controlled manner by athrottling means to the rotary impeller of a turbine or the like havinga work output shaft. This shaft is coupled to a pump for the non-elasticfluid which maintains automatically the necessry circulation demanded bythe operation of the prime mover, and also maintains a near volumetricbalance in the system between the two fluids which are separated byself-adjusting free piston devices. The pump or circulating means forthe non-elastic fluid includes an automatic by-pass for the non-elasticfluid which eliminates the possibility of starving the pump where thelatter depends on the discharge of the non-elastic fluid at low pressurefrom the exhaust of the turbine.-

Other features and advantages of the invention will become apparentduring the course of the following detailed description.

BRIEF DESCRIPTION OF DRAWING FIGURES FIG. 1 is a partly schematic crosssectional view of a closed motive power system embodying the invention.

FIG. 2 is a fragmentary perspective view of a rotary prime moverutilized in the system.

FIG. 3 is an enlarged fragmentary vertical section through the primemover taken normal to its rotational FIG. 4 is an enlarged fragmentaryvertical section taken on line 44 of FIG. 1.

FIG. 5 is a similar section taken on line 5--5 of FIG.

DETAILED DESCRIPTION Referring to the drawings in detail, wherein likenumerals designate like parts throughout, the numeral designates asupply bottle or tank for a compressed elastic fluid, such as air.Preferably, the air in the bottle 10 is compressed to approximately1,500 p.s.i. The compressed air from the bottle 10 is delivered througha suitable pressure regulating valve 11 to the chamber 12 of a highpressure tank 13 on one side of a free piston 14 in the bore of suchtank. The free piston 14 separates the chamber 12 for compressed airfrom a second chamber 15 for an inelastic fluid, such as oil, on theopposite side of the free piston. The free piston 14 is movable axiallywithin the bore of the cylindrical tank 13 and is constantlyself-adjusting therein to maintain a proper volumetric balance betweenthe two separated fluids of the system. The free piston has the abilityto maintain the two fluids, air and oil, completely separated during theoperation of the system.

The regulator valve 11 delivers compressed air to the chamber 12 under apressure of approximately 500 p.s.i. The working inelastic fluid, oil,which fills the chamber 15 of high pressure tank 13 is maintained under500 p.s.i. pressure by the expansive force of the elastic, compressedair in the chamber 12 on the free piston 14.

The oil in the chamber 15 is delivered to a prime mover 16, such as anoil turbine, through a suitable supply regulating or throttle valve 17which controls the volume of pressurized oil delivered to the primemover.

The turbine 16 embodies a stator consisting of a casing ring 18 and endcover plates 19 joined thereto in a fluid tight manner. It furtherembodies a single or plural stage impeller or rotor having bladed wheels20, 21 and 22 in the illustrated embodiment. The peripheral blades 23 ofthese turbine wheels receive the motive fluid from the pressurizedchamber 15 through serially connected nozzles 24, 25 and 26, connectedgenerally tangentially through the stator ring 18, as shown in FIG. 3.The first nozzle 24 shown schematically in FIG. 1 is connected directlywith the outlet of the throttle valve 17. The successive nozzles 25 and26 deliver the pressurized working fluid serially to the blades 23 ofthe turbine wheels 21 and 22, all of the turbine wheels being suitablycoupled to a central axial output or working shaft 27 of the turbine 16.

Fiber back pressure sealing blocks 28 are contained within recesses 29of casing ring 18 to prevent comingling of the working fluid and exhaustat each stage of the turbine. A back pressure sealing block 28 isactually only required in the third stage between inlet 26 and exhaust31, because of the pressure distribution, but such a block can beincluded in each stage as shown in FIG. 1. The top surface including asloping face portion 30 on each block 28 reacts with the pressurizedfluid to maintain the fiber block sealed with the adjacent bladedturbine wheel; and the longer the slope on the block to increase the topsurface area thereof, the greater will be the sealing pressure againstthe periphery of the wheel.

Leading from the final stage of the turbine 16 is a low pressure workingfluid exhaust nozzle 31 which delivers the working fluid, oil, into anoil supply chamber or reservoir 32 of a low pressure tank 33 which maybe bolted to the adjacent end cover plate 19 of the turbine, asindicated at 34. The oil entering the reservoir chamber 32 from theexhaust stage of the turbine is at a pressure of about 3-5 p.s.i. In asecond chamber 35 of the low pressure tank 33 separated from the chamber32 by an automatically moving or self-adjusting free piston 36,compressed air at a balancing pressure of from 3-5 p.s.i. is maintainedby a second pressure regulating valve 37. The pressure regulating valve37 is connected with the compressed air supply line 38 which extendsfrom the regulating valve 11 to the high pressure chamber 12 forcompressed air.

Within the chamber 32 is a gear pump 39 or the like having its inputshaft connected by a coupling 40 with the turbine shaft 27. Suitablereduction gearing 41 for the pump may be provided internally, as shown,or in any other conventional manner, to gear down the rotational speedderived from the turbine shaft. The pump 39 is supplied with the oil inthe filled chamber 32 delivered by the exhaust nozzle or conduit 31 fromthe turbine. The pump, as illustrated, has twin outlet or deliveryconduits 42 each having a back pressure check valve 43 connected thereinand each delivering a like volume of pressurized oil back to the highpressure chamber 15 at a pressure of about 500 p.s.i. The pump 39 alsohas twin fluid inlets. The pump employed is preferably of the type knownon the market as Hydreco Tandem Gear Pump, Model No. 151515, Ll2BL, orequivalent. In some models, other types of pumps could be employedincluding pumps having a single inlet and outlet. The illustrated pumpwill operate clockwise or counter-clockwise and will deliver l4.l g.p.m.at 1,800 r.p.m. and l,500 p.s.i. Therefore, in the present applicationof the pump 39, it will be operating at considerably less than capacityand will be under no strain.

Since the pump depends for its supply of fluid on the delivery of oil atlow pressure from the turbine 16 into the chamber 32, an automaticallyoperating by-pass sleeve valve device 44 for oil is provided asindicated in FIGS. 1, 4 and 5. This device comprises an exterior sleeveor tube 45 having one end directly rigidly secured as at 46 to themovable free piston 36. This sleeve 45 is provided with slots 47intermediate its ends. A coacting interior sleeve 48 engagestelescopically and slidably within the sleeve 45 and has a closed endwall 49 and ports or slots 50 intermediate its ends, as shown. Thesleeve 48 communicates with one of the delivery conduits 42 by way of anelbow 51, and the sleeve 48 is also connected with the adjacent end ofthe pump 39, as shown.

As long as the chamber 32 is filled with low pressure oil sufflcient tobalance the low air pressure in the chamber 35 on the opposite side offree piston 36, such piston will be positioned as shown in FIGS. 1 and 4so that the slots 47 and 50 of the two sleeves 45 and 48 are out ofregistration and therefore noncommunicating. Under such circumstances,the oil from the chamber 32 will enter the pump and will be delivered bythe two conduits 42 at the required pressure to the chamber 15. Shouldthe supply of oil from the turbine 16 to the chamber 32 diminish so thatpump 39 might not be adequately supplied, then the resulting drop inpressure in the chamber 32 will cause the free piston 36 to move to theleft in FIG. 1 and bring the slots 47 into registration or partialregistration with the slots 50, as depicted in FIG. 5. This willinstantly establish a by-pass for oil from one conduit 42 back throughthe elbow 51 and tubes 48 and 45 and their registering slots to the oilchamber 32 to maintain this chamber filled and properly pressurized atall times. The by-pass arrangement is completely automatic and respondsto a diminished supply of oil from the turbine into the chamber 32, solong as the required compressed air pressure of 3-5 p.s.i. is maintainedin the chamber 35.

Briefly, in summary, the system operates as follows. The pressurizedinelastic and non-compressible fluid, oil, from the chamber is throttledinto the turbine 16 by utilizing the throttle valve 17 in a controlstation. The resulting rotation of the shaft 27 produces the requiredmechanical energy or work to power a given instrumentality, such as apropeller. A relatively small component of this work energy is utilizedthrough the coupling 40 to drive the pump 39 which maintains thenecessary volumetric flow of oil from the turbine back into the highpressure chamber 15, with the automatic by-pass 44 coming into operationwhenever needed.

The ultimate source of energy for the closed power system is thecompressed elastic fluid, air, in the tank or bottle 10 which throughthe regulating valves 11 and 37 maintains a constant air pressure in therequired degree in each of the chambers 12 and 35. As described, the airpressure in the high pressure chamber 12 will be approximately 500 psi.and in the low pressure chamber 35 will be approximately 3-5 p.s.i.

It may be observed in FIG. 1 that the tank 33 is enlarged relative tothe tank 13 to compensate for the space occupied by the pump andassociated components. The usable volumes of the two tanks areapproximately equal.

In an operative embodiment of the invention, the two free pistons 14 and36 and the tank bores receiving them are 8 inches in diameter. Theapproximate diameters of the bladed turbine wheels are,18 inches. Thepump 39 is approximately 10 inches long and 5 inches in diameter. Thetank 13 is about 21 inches long between its crowned end walls. The tank33 is l0 inches in diameter adjacent to the pump 39.

The terms and expressions which have been employed herein are used asterms of description and not of limitation, and there is no intention,in the use of such terms and expressions, of excluding any equivalentsof the features shown and described or portions thereof but it isrecognized that various modifications are possible within the scope ofthe invention claimed.

I claim:

l. A power system comprising a high pressure tank and a low pressuretank each having abore, a free piston in the bore of each tank dividingeach tank into separated chambers for elastic and non-elastic fluids, asource of pressurized elastic fluid, pressure regulating meansinterconnected between said source and said chambers of the tanks forelastic fluid so that elastic fluid at a relatively high pressure isdelivered to the high pressure tank and elastic fluid at a relativelylow pressure is delivered to the low pressure tank, a prime mover havinga driven output member and a working fluid inlet and exhaust, saidexhaust communicating with the chamber of the low pressure tank fornonelastic fluid, flow regulating means interconnecting said workingfluid inlet and the chamber of said high pressure tank for non-elasticfluid, and a circulating means for said non-elastic fluid within thechamber of the low pressure tank for non-elastic fluid and coupled withsaid driven output member and operated thereby and having a connectionwith the chamber of the high pressure tank for non-elastic fluid anddelivering such fluid to such chamber.

2. The structure of claim 1, and an automatic by-p'ass device for saidnon-elastic fluid connected with said circulating means and including amovable part connected with the free piston in the bore of the lowpressure tank, whereby movement of the free piston in one directionresponsive to a diminishing of the non-elastic fluid in the low pressuretank will activate the automatic by-pass device and return non-elasticfluid from the circulating means to the chamber of the low pressure tankfor non-elastic fluid.

3. The structure of claim 1, and said source of pressurized elasticfluid comprising a closed container of compressed air.

4. The structure of claim 1, and said pressure regulating meanscomprising a pair of pressure regulating valves.

5. The structure of claim 1, and said prime mover comprising a turbinehaving a rotary impelier, said driven output member being a rotary shaftcoupled with the impeller, said working fluid inlet deliveringnon-elastic fluid to the impeller from the high pressure tank.

6. The structure of claim 5, and said flow regulating means comprisingan adjustable throttle valve.

7. The structure of claim 1, and said circulating means comprising apump having an input drive membet connected with the driven outputmember of the prime mover.

8. The structure of claim 7, wherein said input drive member of the pumpand said driven output member of the prime mover are rotaryshafts, andmeans mechanically coupling said shafts.

9. The structure of claim 2, and said automatic bypass device includinga pair of telescopically interfitting sleeves having fluid flow slotsadapted to assume registering and non-registering positions, one sleeveconstituting said movable part connected with said free piston, wherebymovement of the free piston in said one direction will move said slotsinto registration and thereby activate the by-pass device.

10. The structure of claim 5, and said turbine impeller comprising amultiple stage bladed impeller, said working fluid inlet consisting ofnozzles delivering said non-elastic fluid to the multiple stages of saidimpeller serially, and said exhaust delivering non-elastic fluid fromthe final stage of the impeller to said chamber of the low pressure tankfor non-elastic fluid.

11. The structure of claim 8, wherein said pump is a twin outlet gearpump, each outlet of the pump connected with the chamber of the highpressure tank for non-elastic fluid, and a back pressure check valveconnected in each pump outlet.

12. The structure of claim 11, and said automatic bypass device having aconnection with one outlet of said pump.

1. A power system comprising a high pressure tank and a low pressuretank each having a bore, a free piston in the bore of each tank dividingeach tank into separated chambers for elastic and non-elastic fluids, asource of pressurized elastic fluid, pressure regulating meansinterconnected between said source and said chambers of the tanks forelastic fluid so that elastic fluid at a relatively high pressure isdelivered to the high pressure tank and elastic fluid at a relativelylow pressure is delivered to the low pressure tank, a prime mover havinga driven output member and a working fluid inlet and exhaust, saidexhaust communicating with the chamber of the low pressure tank fornonelastic fluid, flow regulating means interconnecting said workingfluid inlet and the chamber of said high pressure tank for nonelasticfluid, and a circulating means for said non-elastic fluid within thechamber of the low pressure tank for non-elastic fluid and coupled withsaid driven output member and operated thereby and having a connectionwith the chamber of the high pressure tank for non-elastic fluid anddelivering such fluid to such chamber.
 2. The structure of claim 1, andan automatic by-pass device for said non-elastic fluid connected withsaid circulating means and including a movable part connected with thefree piston in the bore of the low pressure tank, whereby movement ofthe free piston in one direction responsive to a diminishing of thenon-elastic fluid in the low pressure tank will activate the automaticby-pass device and return non-elastic fluid from the circulating meansto the chamber of the low pressure tank for non-elastic fluid.
 3. Thestructure of claim 1, and said source of pressurized elastic fluidcomprising a closed container of compressed air.
 4. The structure ofclaim 1, and said pressure regulating means comprising a pair ofpressure regulating valves.
 5. The structure of claim 1, and said primemover comprising a turbine having a rotary impeller, said driven outputmember being a rotary shaft coupled with the impeller, said workingfluid inlet delivering non-elastic fluid to the impeller from the highpressure tank.
 6. The structure of claim 5, and said flow regulatingmeans comprising an adjustable throttle valve.
 7. The structure of claim1, and said circulating means comprising a pump having an input drivemember connected with the driven output member of the prime mover. 8.The structure of claim 7, wherein said input drive member of the pumpand said driven output member of the prime mover are rotary shafts, andmeans mechanically coupling said shafts.
 9. The structure of claim 2,and said automatic by-pass device including a pair of telescopicallyinterfitting sleeves having fluid flow slots adapted to assumeregistering and non-registering positions, one sleeve constituting saidmovable part connected with said free piston, whereby movement of thefree piston in said one direction will move said slots into registrationand thereby activate the by-pass device.
 10. The structure of claim 5,and said turbine impeller comprising a multiple stage bladed impeller,said working fluid inlet consisting of nozzles delivering saidnon-elastic fluid to the multiple stages of said impeller serially, andsaid exhaust delivering non-elastic fluid from the final stage of theimpeller to said chamber of the low pressure tank for non-elastic fluid.11. The structure of claim 8, wherein said pump is a twin outlet gearpump, each outlet of the pump connected with the chamber of the highpressure tank for non-elastic fluid, and a back pressure check valveconnected in each pump outlet.
 12. The structure of claim 11, and saidautomatic by-pass device having a connection with one outlet of saidpump.